Cutting balloon and process

ABSTRACT

A method of preparing a cutting balloon comprises the steps of providing a balloon body having an exterior surface, an unexpanded state and an expanded state; and engaging at least one blade to the exterior surface when the balloon body is in the unexpanded state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/879,894, filed on Jun. 23, 2004, the entire disclosure of which isincorporated herein by reference.

BACKGROUND

Arterial blockages, which are also called stenoses, are typically causedby the build-up of atherosclerotic plaque on the inside wall of anartery. In fact, several such stenoses may occur contiguously within asingle artery. This can result in a partial, or even complete, blockageof the artery. As a result of the danger associated with such ablockage, several methods and procedures have been developed to treatstenoses. One such method is an angioplasty procedure which uses aninflatable balloon to dilate the blocked artery. A typical inflatableangioplasty device, for example, is disclosed in U.S. Pat. No.4,896,669.

Angioplasty balloons have enjoyed widespread acceptance in the treatmentof stenoses. Recent studies, however, have indicated that the efficacyof the dilation of a stenosis is enhanced by first, or simultaneously,incising the material that is creating the stenosis. Consequently,recent developments have been made to equip angioplasty balloons withcutting edges, or atherotomes, which are intended to incise a stenosisduring the dilation procedure. For example, U.S. Pat. No. 5,196,024;U.S. Pat. No. 5,616,149 and U.S. Pat. No. 5,797,935 respectivelydescribe an inflatable angioplasty balloon having a number ofatherotomes mounted longitudinally on the surface of the balloon. Uponinflation of the balloon, the atherotomes induce a series oflongitudinal cuts into the surface of the stenotic material as theballoon expands to dilate the stenosis. As a result of such cuts, thestenosis is more easily dilated, and the likelihood of damaging theartery during dilation is reduced.

In manufacturing a balloon having one or more atherotomes or blades,typically the balloon is inflated and one or more blades are bonded tothe balloon while it remains inflated. The necessity of inflating theballoon in order to position the blades thereon is time consuming andcan lead to additional manufacturing complications as it may bedifficult to position the blades with sufficient accuracy so as maintaina reduced balloon profile and to minimize interference of the bladeswith the folds of the balloon when it is uninflated and loaded onto acatheter for use.

In light of the above it would be desirable to provide a balloon andmethod of manufacturing the same, which presents a balloon having one ormore blades wherein a blade is placed on the balloon body without thenecessity of having to first inflate the balloon.

All US patents and applications and all other published documentsmentioned anywhere in this application are incorporated herein byreference in their entirety.

Without limiting the scope of the invention a brief summary of some ofthe claimed embodiments of the invention is set forth below. Additionaldetails of the summarized embodiments of the invention and/or additionalembodiments of the invention may be found in the Detailed Descriptionbelow.

A brief abstract of the technical disclosure in the specification isprovided as well only for the purposes of complying with 37 C.F.R. 1.72.The abstract is not intended to be used for interpreting the scope ofthe claims.

BRIEF SUMMARY

The present invention is directed to several embodiments. In at leastone embodiment the invention is directed to a medical balloon for usewith a catheter or similar device, wherein the medical balloon isequipped with at least one cutting blade.

In some embodiments, the balloon may be configured for use inconjunction with an implantable medical prosthesis such a stent, graft,stent-graft, vena cava filter, or other similar device hereinaftercollectively referred to as stents.

In at least one embodiment at least one blade is positioned on the outersurface of the balloon. In some embodiments, when the balloon isexpanded the at least one blade defines a substantially spiral-like pathabout the balloon body. In some embodiments, when the balloon isdeflated the at least one blade defines a substantially straight pathalong the balloon body. In some embodiments, when the balloon is foldedinto a reduced profile configuration for passage into a lumen, the atleast one blade is substantially parallel to the longitudinal axis ofthe catheter.

In at least one embodiment the invention is directed to a method ofmanufacturing a medical balloon having at least one blade positionedthereon, wherein the at least one blade is positioned on the balloonwithout having to inflate the balloon.

These and other embodiments which characterize the invention are pointedout with particularity in the claims annexed hereto and forming a parthereof. However, for a better understanding of the invention, itsadvantages and objectives obtained by its use, reference should be madeto the drawings which form a further part hereof and the accompanyingdescriptive matter, in which there is illustrated and describedembodiments of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

A detailed description of the invention is hereafter described withspecific reference being made to the drawings.

FIG. 1 is a side view of an embodiment of the invention wherein theballoon is shown in an unexpanded state.

FIG. 2 is a perspective view of the embodiment shown in FIG. 1 whereinthe balloon is shown in a folded configuration.

FIG. 3 is a perspective view of the embodiment shown in FIG. 2 whereinthe balloon is shown in an expanded state.

DETAILED DESCRIPTION

While this invention may be embodied in many different forms, there aredescribed in detail herein specific preferred embodiments of theinvention. This description is an exemplification of the principles ofthe invention and is not intended to limit the invention to theparticular embodiments illustrated.

For the purposes of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated.

As indicated above, the present invention is embodied in a variety offorms. In at least one embodiment, an example of which is illustrated inFIGS. 1-3, the invention is directed to a balloon 10 for use with acatheter 14, wherein the balloon 10 is equipped with at least oneatherotome, cutting member or blade 12. In the embodiment shown, a blade12 is positioned on the exterior surface 16 of the balloon body 18 sothat when the balloon 10 is expanded, such as in the manner shown inFIG. 3, the blade 12 defines a substantially spiral-like or helical pathabout the circumference of the balloon body 18. A blade 12 is engaged tothe balloon 10 when the balloon 10 is in a deflated, flattened outstate, such as is depicted in FIG. 1.

While there are many ways to engage a blade to a balloon body, such asthe prior art method discussed above, which requires that the balloonbody be expanded in order to position the blade thereon, in at least oneembodiment of the present invention, the invention is directed to amethod wherein a blade 12 is engaged to the exterior surface 16 of theballoon body 18, while the balloon body is in an unexpanded, flattenedout state. Not only does this new method save time and money, itprovides a more simplified mechanism for engaging a blade 12 to theballoon body 18.

In at least one embodiment, after the balloon body 18 has been formedsuch as by extrusion, molding, etc., one or more blades 12, is engagedto the exterior surface 16 of the balloon 10 using any engagement methoddesired. For example, in some embodiments a blade 12 may by engaged tothe balloon body 18 such as by adhesive engagement, mechanicalengagement, etc. In at least one embodiment the blade 12 may bemechanically engaged to the balloon body 18 such as by providing theblade 12 and the exterior surface 16 of the balloon body 18 with one ormore interlocking surface features for mutual securement. In at leastone embodiment a chemical adhesive is applied to one or both of theballoon body 18 and the blade 12 to adhesively engage one to the other.Other mechanisms for engaging blade 12 to the balloon body 18 may alsobe utilized.

The balloon body 18 may be made of any suitable balloon materialincluding compliant and non-compliant materials and combinationsthereof. Some examples of suitable materials for constructing theballoon body 18 include but are not limited to: low pressure, relativelysoft or flexible polymeric materials, such as thermoplastic polymers,thermoplastic elastomers, polyethylene (high density, low density,intermediate density, linear low density), various co-polymers andblends of polyethylene, ionomers, polyesters, polyurethanes,polycarbonates, polyamides, poly-vinyl chloride,acrylonitrile-butadiene-styrene copolymers, polyether-polyestercopolymers, and polyetherpolyamide copolymers; copolymer polyolefinmaterial available from E.I. DuPont de Nemours and Co. (Wilmington,Del.), under the trade name Surlyn™; ionomer and a polyether block amideavailable under the trade name PEBAX™; high pressure polymericmaterials, such as thermoplastic polymers and thermoset polymericmaterials, polyethylene terephthalate) (commonly referred to as PET),polyimide, thermoplastic polyamide, polyamides, polyesters,polycarbonates, polyphenylene sulfides, polypropylene and rigidpolyurethane; one or more liquid crystal polymers; and combinations ofone or more of any of the above.

Blade 12 may be constructed from one or more metals, polymers,combinations of one or more metals and/or polymers, and/or other desiredmaterial(s). In at least one embodiment, blade 12 is at least partiallyconstructed of a shape memory material, such as nitinol and/or a shapememory polymer. The blade 12 may comprise a plurality of separate bladesegments or may be a single continuous structure as desired.

As may be seen in FIG. 1, a convenient aspect of affixing blade 12 toballoon body 18 in the unexpanded state is that the blade 12 may beengaged to the balloon body 18 while the blade 12 is in a substantiallylinear configuration and the balloon 10 is substantially flattened outor “pancaked”. In at least one embodiment, the blade 12 is substantiallystraight when it is engaged to the exterior surface 16 of the flattenedballoon body 18. That is to say, it is not necessary to provide theblade 12 with one or more bends or curves (such as would be necessarywhen affixing a blade to a balloon in the expanded state) when the blade12 is engaged to the exterior surface 16 of the balloon body 18, unlesssuch features are desired.

In at least one embodiment, when the balloon body 18 is in theunexpanded “flattened” state the exterior surface 16 of the balloon body18 comprises four corner regions. This is true even in the case of asubstantially cylindrical shaped balloon when it is flattened in theunexpanded state. The corner regions may be described by theirrespective orientation such as: a proximal top corner 20, a proximalbottom corner 22, a distal top corner 24 and a distal bottom corner 26.

In order to provide the balloon 10 with a blade 12 having asubstantially spiral-like configuration in the expanded state, such asis shown in FIG. 3, the blade 12 is engaged to the balloon body 18 inthe unexpanded state so that the ends 30 and 32 of the blade 12 arepositioned in opposite corner regions such as in the manner shown inFIG. 1. For example, an end of the blade 12 may be positioned in theproximal top corner 20 while the other end is positioned in the distalbottom corner 26 of the unexpanded balloon body 18. In some embodimentsa blade end is be positioned in the proximal bottom corner 22 and theother blade end is positioned in the distal top corner 24.

If desired, the blade 12 may be positioned in any manner desired uponthe balloon body 18. The opposing corner to corner, substantially linearconfiguration of the balloon 10 shown in FIG. 1 is an embodiment whichwill provide the substantially spiral-like blade orientation shown inFIG. 3. It is recognized that other configurations may be desired, suchas for example, a blade 12 may be engaged to the balloon body 18 so thatin the expanded state the balloon 10 is provided with a blade or blades12 that are substantially longitudinally disposed, radially disposed orotherwise positioned or disposed about the balloon body 18. As such, ablade 12 may be engaged to the balloon body 18 in the unexpanded statewith any orientation in order to provide the balloon 10 in the expandedstate with a blade 12 that has any configuration desired.

Where the balloon 10 is produced separately from the shaft 13 of thecatheter 14, the blade 12 may be engaged to the balloon body 18 beforeor after the balloon 10 is affixed to the catheter shaft 13.

Once blade 12 is engaged to the balloon body 18, and the balloon 10 isengaged to the catheter shaft 13, the unexpanded balloon 10 is foldedand/or wrapped, such as in the manner shown in FIG. 2 in order to attaina reduced profile configuration suitable for advancement within a bodylumen or vessel.

In some embodiments the catheter 14 may be configured to deliver one ormore therapeutic agents to an stenosis, aneurysm or lesion within a bodylumen. In some embodiments at least a portion of the blade 12 isconfigured to include one or more holes, notches, or other surfacefeatures for use in delivering one or more therapeutic agents to alesion. A therapeutic agent may be placed on the blade 12 and/or theexterior surface 16 of the balloon body 18 in the form of one or morecoatings. In at least one embodiment the coating includes at least onetherapeutic agent and at least one polymer.

A therapeutic agent may be a drug or other pharmaceutical product suchas non-genetic agents, genetic agents, cellular material, etc. Someexamples of suitable non-genetic therapeutic agents include but are notlimited to: anti-thrombogenic agents such as heparin, heparinderivatives, vascular cell growth promoters, growth factor inhibitors,Paclitaxel, etc. Where an agent includes a genetic therapeutic agent,such a genetic agent may include but is not limited to: DNA, RNA andtheir respective derivatives and/or components; hedgehog proteins, etc.Where a therapeutic agent includes cellular material, the cellularmaterial may include but is not limited to: cells of human origin and/ornon-human origin as well as their respective components and/orderivatives thereof. Where the therapeutic agent includes a polymeragent, the polymer agent may be apolystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS),polyethylene oxide, silicone rubber and/or any other suitable substrate.

The above disclosure is intended to be illustrative and not exhaustive.This description will suggest many variations and alternatives to one ofordinary skill in this art. All these alternatives and variations areintended to be included within the scope of the claims where the term“comprising” means “including, but not limited to”. Those familiar withthe art may recognize other equivalents to the specific embodimentsdescribed herein which equivalents are also intended to be encompassedby the claims.

Further, the particular features presented in the dependent claims canbe combined with each other in other manners within the scope of theinvention such that the invention should be recognized as alsospecifically directed to other embodiments having any other possiblecombination of the features of the dependent claims. For instance, forpurposes of claim publication, any dependent claim which follows shouldbe taken as alternatively written in a multiple dependent form from allprior claims which possess all antecedents referenced in such dependentclaim if such multiple dependent format is an accepted format within thejurisdiction (e.g. each claim depending directly from claim 1 should bealternatively taken as depending from all previous claims). Injurisdictions where multiple dependent claim formats are restricted, thefollowing dependent claims should each be also taken as alternativelywritten in each singly dependent claim format which creates a dependencyfrom a prior antecedent-possessing claim other than the specific claimlisted in such dependent claim below.

This completes the description of the preferred and alternateembodiments of the invention. Those skilled in the art may recognizeother equivalents to the specific embodiment described herein whichequivalents are intended to be encompassed by the claims attachedhereto.

1. A balloon catheter, comprising: an elongate catheter shaft; aninflatable balloon secured to a distal end region of the catheter shaft;a cutting member positioned along an exterior surface of the balloon,the cutting member including surface features for maintaining atherapeutic agent thereon; and a therapeutic agent disposed in thesurface features of the cutting member for delivery to a treatment sitewith the cutting member.
 2. The balloon catheter of claim 1, wherein thecutting member is helically disposed about the exterior surface of theballoon.
 3. The balloon catheter of claim 1, wherein the cutting memberis secured to the exterior surface of the balloon.
 4. The ballooncatheter of claim 1, wherein the surface features include one or moreholes in a surface of the cutting member.
 5. The balloon catheter ofclaim 4, wherein the therapeutic agent is disposed in the one or moreholes of the cutting member.
 6. The balloon catheter of claim 1, whereinthe surface features include one or more notches in a surface of thecutting member.
 7. The balloon catheter of claim 6, wherein thetherapeutic agent is disposed in the one or more notches of the cuttingmember.
 8. The balloon catheter of claim 1, further comprising a coatingon the exterior surface of the balloon including a therapeutic agent. 9.A cutting balloon catheter, comprising: an elongate catheter shaft; aninflatable balloon secured to a distal end region of the catheter shaft;a plurality of cutting members arranged along a exterior surface of theballoon; and a therapeutic agent disposed on the cutting members;wherein the cutting members include surface characteristics formed in asurface of the cutting members for receiving the therapeutic agent fordelivery to a treatment site.
 10. The cutting balloon catheter of claim9, wherein the surface characteristics include one or more holes in thesurface of the cutting member.
 11. The cutting balloon catheter of claim10, wherein the therapeutic agent is disposed in the one or more holesof the cutting member.
 12. The cutting balloon catheter of claim 9,wherein the surface characteristics include one or more notches in thesurface of the cutting member.
 13. The cutting balloon catheter of claim12, wherein the therapeutic agent is disposed in the one or more notchesof the cutting member.
 14. The cutting balloon catheter of claim 9,wherein the therapeutic agent is included in a coating on the surface ofthe cutting member.
 15. The cutting balloon catheter of claim 9, whereinthe plurality of cutting members are helically arranged about acircumference of the balloon.
 16. A balloon catheter comprising: anelongate catheter shaft; an inflatable balloon secured to a distal endregion of the catheter shaft; a cutting member positioned along anexterior surface of the balloon; a therapeutic agent for delivery to atreatment site; and means for retaining the therapeutic agent to asurface of the cutting member.
 17. The balloon catheter of claim 16,wherein the means for retaining the therapeutic agent to a surface ofthe cutting member includes one or more holes in the surface of thecutting member.
 18. The balloon catheter of claim 17, wherein thetherapeutic agent is disposed in the one or more holes of the cuttingmember.
 19. The balloon catheter of claim 16, wherein the means forretaining the therapeutic agent to a surface of the cutting memberincludes one or more notches in a surface of the cutting member.
 20. Theballoon catheter of claim 19, wherein the therapeutic agent is disposedin the one or more notches of the cutting member.